1. Field of the Invention
The present invention relates generally to the field wireless data communications, and more particularly, to data communication between a handheld device having an optical interface port that transmits and receives signals with an optical interface port of an electronically operated appliance.
2. Technical Background
Standard infrared (IR) devices communicate in accordance with the Infrared Data Association Serial Infrared Physical Layer Specification (hereinafter referred to as the Serial Infrared Specification) promulgated by the Infrared Data Association (IrDA). The IrDA is a standard body that publishes specifications containing the criteria by which IR device manufacturers must comply in order to claim IrDA compliance. The Infrared Data Association Serial Infrared Specification is incorporated herein by reference.
The physical layer specification governs point-to-point communication between electronic devices, such as computers and peripherals, using directed half-duplex, serial infrared communication links through free space. The physical elements, including the optical links and active input and output interfaces, are described in the physical layer specification. In order for a device to be IrDA compliant, the device must be designed to meet the specifications as indicated in the physical layer specification.
In particular, the IrDA Physical Layer Specification places constraints on the communication procedure when a device attempts to establish an optical link with a second device. The IrDA Physical Layer Specification sets forth requirements that govern the behavior of a device having a transmitter/detector pair when establishing an optical link. Compliance with the IrDA Physical Layer Specification requires that the device sample its detection range. An IrDA compliant device will not transmit a pulse to another device to request a link until it detects 500 msecs of “media quiet.” “Media quiet” means that there is no IR activity detected during the 500 msec duration.
Once an optical link is established between two devices, IrDA compliance requires that a serial interaction pulse (SIP) be emitted every 500 msecs to quiet other potentially interfering systems. In other words, the 500 msec “media quiet” requirement will ensure that the potentially interfering device detects an SIP every 500 msecs thereby precluding the device from attempting to establish a connection.
The SIP is required by the Physical Layer Specification to quiet slower systems that might interfere with the optical link established between the transmitter and the receiver. An SIP is a 1.6 microsecond pulse followed by a 7.1 microsecond off time of the transmitter. The SIP simulates a start pulse that requires a potentially interfering system to listen for at least 500 milliseconds prior to establishing an optical link.
In accordance with the Physical Layer Specification, optical sensors are commonly employed with IR transmitters which, together with processing electronics, are used to detect an object in the range of the IR transmitter. An IR pulse is emitted, and if it strikes an object in its range, the pulse is reflected. An IR sensor is placed strategically in order to detect the reflected pulse.
The dichotomous emitter/sensor technology is employed in various applications including electronically activated fluid dispensing devices. Such dispensing systems, such as hand activated water faucets, generally include an infrared emitter that emits a timed pulse. When an object, such as a user's hands, is within the emitter's range, it reflects the pulsed IR beam, and the optical sensor detects the reflected light from the user's hands. In such a system, an IrDA compliant device emits a pulse every 250 milliseconds.
Various methods have been employed to electronically control water flow through a water control device such as a faucet or spigot. Among the accepted methods is the use of an optical sensor typically employed in combination with an infrared (“IR”) source or IR emitter that together with processing electronics, are used to control a solenoid valve. Generally speaking, a pulsed IR beam is reflected from an object (such as a user's hands or other body parts, for example) and sensed by a photo detector to determine whether to activate or deactivate the solenoid valve. Pulsed IR sensing remains at the forefront of sensing techniques used with these types of devices, due in part to its reasonable performance and low cost.
Automatically activated fluid dispensing devices commonly known in the art do have a myriad of operating shortcomings. For example, devices such as IR controlled faucets require extensive manual servicing and maintenance. Inherently, in an environment such as an office building having numerous floors and numerous faucets in each of the restrooms on each of the floors, servicing and maintenance of the IR controlled devices is often a burdensome and time consuming task. Many simple tasks associated with the maintenance of the faucets, including battery replacement, IR range monitoring, and solenoid malfunction detection, are typically manually performed per faucet per restroom per floor in an office building. This type of monitoring of malfunctioning units dictates manual interaction with each unit for diagnostics, maintenance, calibration, and servicing.
In addition, a common denominator for many of the problems associated with automatically activated flow control devices, such as faucets, is the environment in which such devices are installed and operate. For instance, existing IR sensor designs generally suffer from an inability to adapt to changes in the background signal level associated with a gradual discoloration of the sink in which the faucet is mounted, a gradual degradation of the sensor lens due to the use of abrasive cleaning compounds, a gradual degradation of the IR emitter performance, among other things. Generally, existing sensors employ a fixed sensitivity threshold that is set either at the factory or by the installer (or both). When the IR sensor sensitivity is fixed, the sensors performance will inevitably degrade with environmental changes, and when the degradation causes faulty operation, a service call may be required. In some instances, the gradual degradation will go unnoticed resulting in poor performance.
In addition, calibration of today's automatically activated flow control devices is often labor intensive and inefficient with respect to devices presently on the market. The low cost IR sensing devices employed in automatically activated flow control devices vary with respect to power requirements, performance, and other criteria. As a result, readings taken by these IR sensing units (such as whether a user's hands are present beneath the aerator of a faucet) are generally nonuniform from device to device and, therefore, often result in improper activation and deactivation of some devices. Similarly, as battery power for these devices decreases over time, so does the power output of the IR sensing devices. As a result, manual calibration of conventional automatically activated flow control devices is generally required during initial installation, and thereafter on a frequent basis following extended periods of use.
Unfortunately, vandalism and water damage also adversely affect the use and proper operation of automatically activated flow control devices presently available in the art. Water often travels along the wiring harness extending from the flow control device to the device's electronics causing corrosion to the parts. In addition, vandals may attempt to break into the electronics box associated with the device or pull the wires from either the electronics box or the faucet.
What is needed therefore, but presently unavailable in the art is a system and method of wireless two-way data exchange between an appliance such as, an electronically activated flow control device, and a handheld device that overcomes many of the shortcomings associated with electronically activated appliances presently available in the art. Such a system and method should be easily maintained by maintenance personnel, substantially impervious to vandalism, self-calibrating, and remotely controlled. In addition, the system of the present invention should be capable of being remotely managed and controlled by any number of portable communication devices presently available in the art. The system should consume low power, be easy to install, and low cost. Moreover, the system should be capable of receiving instruction from a remote IRDA emitting device despite the appliances rapid rate of emitted IR sensing pulses. Large numbers of appliances within the system should also be capable of being used in a distributed network environment, and should be adapted to be managed and controlled from as few as one centralized control point. It is to the provision of such a system and method that the present invention is primarily directed.